Stone,
Jammed cases when you shut the gas completely off is normal in an AR. You need at least some gas to free that initial jam. This is why in Post#297 I recommended shutting it off almost completely (but not completely). Then shooting and opening the gas up slowly with 1-round mags until it locks back reliably on last round - but go no further.
As it is looking like aggravated early unlocking then your gas block should be enough with a heavier buffer. Spending more money on after-market springs and adjustable carriers will also work, but the cheapest option is to use what you already have and swap the buffer for a heavier one.
If the mouth of the chamber is too wide to be supportive then that is an issue that only a new barrel from a different manufacturer will fix. Fixing the early unlocking might solve the magnum belting and catastrophic ruptures, but it my still be on the edge of brass longevity. If the brass is now OK however, and brass longevity is within you definition of reasonable then problemo solvered.
Jammed cases when you shut the gas completely off is normal in an AR. You need at least some gas to free that initial jam. This is why in Post#297 I recommended shutting it off almost completely (but not completely). Then shooting and opening the gas up slowly with 1-round mags until it locks back reliably on last round - but go no further.
As it is looking like aggravated early unlocking then your gas block should be enough with a heavier buffer. Spending more money on after-market springs and adjustable carriers will also work, but the cheapest option is to use what you already have and swap the buffer for a heavier one.
If the mouth of the chamber is too wide to be supportive then that is an issue that only a new barrel from a different manufacturer will fix. Fixing the early unlocking might solve the magnum belting and catastrophic ruptures, but it my still be on the edge of brass longevity. If the brass is now OK however, and brass longevity is within you definition of reasonable then problemo solvered.